2,994 research outputs found
Kinematic and kinetic patterns related to free-walking in parkinson’s disease
The aim of this study is to compare the properties of free-walking at a natural pace between mild Parkinson’s disease (PD) patients during the ON-clinical status and two control groups. In-shoe pressure-sensitive insoles were used to quantify the temporal and force characteristics of a 5-min free-walking in 11 PD patients, in 16 young healthy controls, and in 12 age-matched healthy controls. Inferential statistics analyses were performed on the kinematic and kinetic parameters to compare groups’ performances, whereas feature selection analyses and automatic classification were used to identify the signature of parkinsonian gait and to assess the performance of group classification, respectively. Compared to healthy subjects, the PD patients’ gait pattern presented significant differences in kinematic parameters associated with bilateral coordination but not in kinetics. Specifically, patients showed an increased variability in double support time, greater gait asymmetry and phase deviation, and also poorer phase coordination. Feature selection analyses based on the ReliefF algorithm on the differential parameters in PD patients revealed an effect of the clinical status, especially true in double support time variability and gait asymmetry. Automatic classification of PD patients, young and senior subjects confirmed that kinematic predictors produced a slightly better classification performance than kinetic predictors. Overall, classification accuracy of groups with a linear discriminant model which included the whole set of features (i.e., demographics and parameters extracted from the sensors) was 64.1%
Short communication. Collection and characterisation of a population of Triticum boeoticum Boiss., a wild wheat species not previously found in the Mediterranean western region
En julio del 2010 se recolectó una población de trigo silvestre en una zona abandonada cerca de Madrid, España.
Esta zona posee una biodiversidad botánica elevada y un tipo de suelo muy peculiar denominado “arcillas verdes”. Se
recogió una muestra de trigo y se multiplicó y caracterizó para varios caracteres agro-morfológicos y subunidades de
gluteninas. El número cromosómico 2n de las semillas demostró que es una especie diploide de trigo y los datos de
caracterización indicaron que es Triticum boeoticum Boiss. Esta especie llegó probablemente como mala hierba del
cultivo de escaña que se producía en la zona hasta al menos la primera mitad del s. xix. Las características edáficas y
climáticas del lugar y el hecho de que no haya referencias hasta ahora de esta especie en la zona oeste de la región
Mediterránea aumentan el valor de esta adquisición para la mejora del trigo. La nueva accesión se conserva en el Centro
Nacional de Recursos Fitogenéticos y se ha depositado una hoja de herbario en el Real Jardín Botánico de Madri
Design of a 35 kW Solar Cooling Demonstration Facility for a Hotel in Spain
[EN] Solar cooling systems have the advantage of the coincidence between the hours of cooling
demand and the hours of solar radiation availability, and they can contribute to reduce the energy
consumption in buildings. However, the high cost of thermal solar cooling facilities with absorption
chillers, maintenance issues, legionella risk and water consumption (associated to the necessary
cooling tower) have limited the use of these systems to demonstration projects. A simplified
Transient System Simulation Tool (TRNSYS) model was developed to provide the owner of the
demonstration facility the information he needs for design decision-making. This model was
validated with experimental data registered in a solar cooling system designed and built by the
authors. Different collector field surfaces, hot water storage tank volumes, and absorption machine
driving temperatures were analyzed for a hotel demonstration facility. In terms of the energy
delivered to the absorption chiller the optimum dimensioning corresponded to the lowest values of
the driving temperature (75 °C) and specific storage volume (15 Lm2). From an economic point of
view, the saving of 1515 euros per year when compared with an electric compression chiller does
not compensate the investment of 3000 euros per kW of cooling capacity that cost the thermal solar
cooling facility.This research was funded by (MINECO/AEI/FEDER, UE), grant number ENE2017-83729-C3-1-R.Martínez, PJ.; Martínez, P.; Soto Francés, VM.; Bujedo, LA.; Rodríguez, J. (2020). Design of a 35 kW Solar Cooling Demonstration Facility for a Hotel in Spain. Applied Sciences. 10(496):1-13. https://doi.org/10.3390/app10020496S1131049
Minimization of measuring points for the electric field exposure map generation in indoor environments by means of Kriging interpolation and selective sampling
In a world with increasing systems accessing to radio spectrum, the concern for exposure to electromagnetic fields is growing and therefore it is necessary to check limits in those areas where electromagnetic sources are working. Therefore, radio and exposure maps are continuously being generated, mainly in outdoor areas, by using many interpolation techniques. In this work, Surfer software and Kriging interpolation have been used for the first time to generate an indoor exposure map. A regular measuring mesh has been generated. Elimination of Less Significant Points (ELSP) and Geometrical Elimination of Neighbors (GEN) strategies to reduce the measuring points have been presented and evaluated. Both strategies have been compared to the map generated with all the measurements by calculating the root mean square and mean absolute errors. Results indicate that ELSP method can reduce up to 70% of the mesh measuring points while producing similar exposure maps to the one generated with all the measuring points. GEN, however, produces distorted maps and much higher error indicators even for 50% of eliminated measuring points. As a conclusion, a procedure for reducing the measuring points to generate radio and exposure maps is proposed based on the ELSP method and the Kriging interpolation.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
Insulation Design of Low Voltage Electrical Motors Fed by PWM Inverters
This paper proposes a model to determine the partial discharge inception voltage of magnet wires, including the effect of elevated temperatures, and shows its applicability to the complete range of wire geometries considered in IEC Standard 60317-13
Building Suitable Datasets for Soft Computing and Machine Learning Techniques from Meteorological Data Integration: A Case Study for Predicting Significant Wave Height and Energy Flux
Meteorological data are extensively used to perform environmental learning. Soft Computing (SC) and Machine Learning (ML) techniques represent a valuable support in many research areas, but require datasets containing information related to the topic under study. Such datasets are not always available in an appropriate format and its preparation and pre-processing implies a lot of time and effort by researchers. This paper presents a novel software tool with a user-friendly GUI to create datasets by means of management and data integration of meteorological observations from two data sources: the National Data Buoy Center and the National Centers for Environmental Prediction and for Atmospheric Research Reanalysis Project. Such datasets can be created using buoys and reanalysis data through customisable procedures, in terms of temporal resolution, predictive and objective variables, and can be used by SC and ML methodologies for prediction tasks (classification or regression). The objective is providing the research community with an automated and versatile system for the casuistry that entails well-formed and quality data integration, potentially leading to better prediction models. The software tool can be used as a supporting tool for coastal and ocean engineering applications, sustainable energy production, or environmental modelling; as well as for decision-making in the design and building of coastal protection structures, marine transport, ocean energy converters, and well-planned running of offshore and coastal engineering activities. Finally, to illustrate the applicability of the proposed tool, a case study to classify waves depending on their significant height and to predict energy flux in the Gulf of Alaska is presented
Acoustic Transmitters for Underwater Neutrino Telescopes
In this paper acoustic transmitters that were developed for use in underwater
neutrino telescopes are presented. Firstly, an acoustic transceiver has been
developed as part of the acoustic positioning system of neutrino telescopes.
These infrastructures are not completely rigid and require a positioning system
in order to monitor the position of the optical sensors which move due to sea
currents. To guarantee a reliable and versatile system, the transceiver has the
requirements of reduced cost, low power consumption, high pressure withstanding
(up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary
signals for emission and the capacity of acquiring and processing received
signals. Secondly, a compact acoustic transmitter array has been developed for
the calibration of acoustic neutrino detection systems. The array is able to
mimic the signature of ultra-high-energy neutrino interaction in emission
directivity and signal shape. The technique of parametric acoustic sources has
been used to achieve the proposed aim. The developed compact array has
practical features such as easy manageability and operation. The prototype
designs and the results of different tests are described. The techniques
applied for these two acoustic systems are so powerful and versatile that may
be of interest in other marine applications using acoustic transmitters.Comment: 21 pages, 14 figures,1 tabl
Effect of carrier transfer on the PL intensity in self-assembled In (Ga) As/GaAs quantum rings
We present results concerning the carrier transfer between In(Ga)As quantum rings in a stacked multilayer structure, which is characterised by a bimodal size distribution. This transfer of carriers explains the observed temperature behaviour of diode lasers based on that kind of stacked layer structures. The inter-ring carrier transfer can be possible by phonon assisted tunnelling from the ground state of the smallring family towards the big-ring family of the bimodal size distribution. This process is thermally activated in the range 40–80 K.This work was partially supported by Spanish MCyT Nanoself I and II projects TIC2002-04096-C03 and TEC2005-05781-C03-03, the SANDiE Network of excellence (Contract No.
NMP4-CT-2004-500101) and the AECI Spain-Tunisia bilateral research action No. 2/04/R.Peer reviewe
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